Predictors of atopic dermatitis phenotypes and severity: roles of serum immunoglobulins and filaggrin gene mutation R501X.

BACKGROUND

Atopic dermatitis (AD), the most common chronic relapsing skin condition of infancy and childhood, is a complex multifactorial disease, which arises from the interaction between strong genetic and environmental factors.

OBJECTIVE

To investigate the roles of several factors on the severity of AD including FLG R501X gene mutation, serum immunoglobulin (Ig) levels, atopy and accompanying allergic disorders.

METHOD

Children were genotyped for the mutation in FLG R501X gene. Serum levels of major Ig isotypes, atopy and accompanying allergic disorders were assessed.

RESULTS

Study group consisted of 49 patients (M: 26, F: 23) with a mean age of 4.9±3.6 years and control group consisted of 50 children (M: 30, F: 20) with a mean age of 3.8±2.8 years. Genotyping of R501X mutation revealed risk alleles in none of the children in study group or control group. IgG z-scores were significantly higher in patients with AD compared to controls (-0.97±1.13 vs 1.48±1.02, p=0.026). There was a positive trend in IgG z-scores and a negative trend in IgA z-scores across the severity of AD. History of recurrent infections was significantly associated with asthma and/or AR (47.8% in patients with asthma/AR vs 3.8% in those without). Children with low IgG or IgA levels presented at an earlier age with lower rates of atopy and mild type AD.

CONCLUSION

In a sample of Turkish children, FLG R501X genotyping revealed no risk alleles in variable severities of AD or healthy controls. Our data suggest that IgG and IgA levels might have a role in phenotypic features of AD in terms of severity and atopic sensitisation.